Check-valve mechanism



, s. L. KNEASS CHECK VALVE MECHANISM If'iled April 10. 1922 2shets-sneet 1 June 2,

S. L. KNEASS CHECK VALVE MECHANISM Filed April l0, 1922 2 Sheets-Shut 2s N J W mw m W Patented June 2, 1925.

UNITED STATES PATENT OFFICE.

O STRICKLAND L, KNEASS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TWILLIAM SELLERS & COMPANY, INCORPORATED, 0F PHILADELPHIA, PENNSYLVANIA,A

CORPORATION OF PENNSYLVANIA.

CHECK-VALVE MECHANISM.

Application filed April 10, 1922. Serial No. 551,091.

To all whom it may concern:

Be it known that I, STRICKLAND L.

KNnAss, a citizen of the United States, re-

siding at Philadelphia, county of Phila- 6 delphia, and State ofPennsylvania, have invented a new and useful Improvement in Check-ValveMechanism, of which the following is a full, clear, and exactdescription, reference being had to the accompany- 1 ing drawings, whichform a part of this specification.

My invention relates to valve mechanism for controlling the flow ofpressure fluid to apressure chamber or reservoir, especially where themotion of the entering fluid is intermittent, as, for example, where apump is used to supply water to a locomotive or stationary boiler.Inasmuch as the pressure in the feed pipe fluctuates between limitsabove and below the pressure in the boiler or pressure reservoir, acheckvalve is used to, prevent back flow, which check valve moves to andfrom 1ts seat 1n responseto such pressurev fluctuation. This causes wearseat. Merely lessening the lift and increasing the area of the passagemay involve an increase of superimposed pressure and weight of valve,yielding little advantage. One object of my invention is to provide acheck valve construction in which the inertia and impact of the valvewill be substantially reduced so that there will be minimum wear of bothvalve and seat.

Another object of my invention is to prevent back flow of fluid from thereservoir or boiler in case it is desired to grind, repair or replacethe check valve, thereby securing ease and cheapness of repair.

Embodiments of my invention are shown in the accompanying drawings, inwhich- Fig. 1 is a vertical sectional -view of simplified valvemechanism embodying my invention.

Fig. 2 is a section on theline 2--2 of Fig. 1, with the stop valveremoved. Fig. 3 is a view, similar to Fig. 1, of an alternativeconstruction embodying my invention.

Fig. 4 is a section on the line 44 of Fig. 3.

Fig. 5 is an enlarged sectional View of a detail of the structure ofFigs. 3 and 4.

Fig. 6 is an enlarged sectional view of a parts destructive to the valveand thev modification of the structure of Figs. 1 and 2.

Referring first to the construction show in Figs. 1 and 2:

The valve casing a encloses an inlet chamcarrying-a ring 71 extendingabove, and

spaced from, the opening between the outer and inner valve seats 6 and fand forming a stop limiting the unseating movement of the valve. Thewebs h are provided with extensions h which form a guide for the thin,annular, flexible disc-valve k.

In the discharge chamber of the valve casing a is a valve seat m andvalve 01., the latter being normally open so as to allow a whollyunrestricted flow of fluid. The body of the valve is threaded in anopening in the discharge'chamber 0 of the casing a and is adapted to bescrewed onto its seat so as to completely separate the check valvechamber from the boiler or reservoir.

The area of discharge is determined by a circumference of thedischarging passage way under the valve when the valve is lifted and bythe lift of the valve. The shorter the lift of a valve, the less itsmomentum and (with a given weight of valve) the lighter the blow uponits seat. By providing an outer valve seat of maximum practicaldiameter, the lift of the valve ma be reduced toa minimum, thereby solig tening the energy of the blow as to minimize the damaging effectupon the valve The blow seat and upon the valve itself. struck by thevalve being a light one, the valve need not be made heavy to withstandthe shock, but ma be relatively light and thin, and just su cientlystrong to withstand the superimposed pressure and blow when seating.

In my invention I provide two areas of discharge of a single valve bymaking the valve annular and discharging from under both its inner andouter circumferences and thus obtain the largest area of discharge witha minimum lift; and I use a light valve seating upon inner and outerconcentric Septums, which owing to strain and stress in service areliable to distortion from their normal alignment and require that thevalve be sufliciently thin to provide the flexibility required to seatfluid-tight. If the valve be annular, as shown, it should besufficiently flexible to seat fluid-tight upon its outer rim as well asupon its inner rim.

Under certain circumstances, it may be advantageous to provide for afluid-tight seat upon the outer rim only of the annular valve, theconstruction shown in figs. 8, 4 and 5 may be adopted. In thisconstruction, the unseating movement of the annular disc-valve r islimited by lugs 0 depending from the removable head 1). Above the valve1' is a flexible circular disc valves having a circumferential flangefor the purpose of guiding it when lifting from its seat. The septum uis provided with an outer circumferential valve seat '0, a central seator stop for the valve 8 and an intermediate concentric member 11;corresponding to the valve seat f of Fig. 1, although not necessarilybeing ground to afford a fluid-tight seat. The upward movement of thevalve r is limited by the lugs or stops 0. The upward movement of thevalve .9 is limited by shoulders w on the lugs 0, said lugs also forminga gulde to maintain valve 8 in proper alignment. When the pressure onthe inlet side exceeds the pressure on the outlet side, the valves 1'and s are both lifted, affording flow passages under the outer edge ofthe annular valve 1- and under the superimposed circular valve 8, asindicated by arrows in Fig. 5. Upon reversal of pressure, the annularvalve 1' seats fluid-tight against the seat o and the outer rim of thecircular valve 3 seats fluidtight upon the inner rim of the annularvalve.

The construction shown in Figs. 1 and 2 is, by reason of its simplicity,preferable to that shown in Figs. 3, 4 and 5, but may require, undercertain pressure conditions and degrees of elasticity and resilience ofthe valve disc is, a slight deviation from the plane surface of theconcentric valve seats, due to a possible tendency of the valve disc tobend slightly into a concave shape and when in that shape it seatsfluid-tight only against the corners of the valve seats 6 and f and notabsolutely flat against the entire area of the valve seat faces. Ihave,'-however, overcome this objection by making the valve seatslightly concave, as shown, much exaggerated, at 2 in Fig. 6. The discvalve should be of flexible and elastic material with a normal flatcontour, as shown in full lines at s, Fig. 6, and adapted, upon seating,

to yield or flex suifleiently' to conform to its seat, as shown indotted lines.

Not only does the lightness of the blow upon seating reduce the wearupon valve and seat that causes upsetting of the material, but it avoidsor materially reduces the damage arising from particles of foreignmatter being caught between the two surfaces at the time of seating.'With a heavy valve having a substantial lift and which seats with aheavy blow, especially when the feed is supplied to the reservoirintermittently, as by a pump, such foreign material so caught is, byreason of the heavy blow aforesaid, driven into the seating surface ofthe valve, with consequent damage causing fluid leakage. With a valveembodying my invention, having both a minimum weight and a minimum lift,the energy of the blow is reduced to a minimum and such foreign matteris not driven into the material; but during the next flow of fluid underthe valve, the foreign materialis washed away and the valve surfacesremain undamaged and fluid-tight.

Having now fully described my invention, what I claim and desire toprotect by Letters Patent is:

1. A valve mechanism interposed between a source of pressure fluidsupply and a vpressure fluid reservoir comprising a. valvebody, a septumdividing the body into inlet and outlet chambers and provided with anannular opening circumscribed by concentric raised seats, and a lightresilient annular valve, said valve adapted to flex under superimposedpressure to conform to said seats and bear on the surfaces thereof.

2. A valve mechanism interposed between a source of pressure fluidsupply and a pres sure fluid reservoir comprising a valve casing, aseptum dividing the easing into an inlet chamber and an outlet chamber,a light disc-like flexible annular valve, a light disclike flexiblecircular valve of smaller diameter than the annular valve and positionedabove and adapted to seat thereon, said septum having a plurality ofconcentric faces affording a seat for said annular valve, and meansadapted to limit the lift of salid valves respectively.

3. A valve mechanism interposed between a source of pressure fluidsupply and a pressure fluid reservoir comprising a valve casing, aseptum dividing the easing into an inlet chamber and an outlet chamber,a light disc-like flexible annular valve, a light disclike flexiblecircular valve of smaller diameter than the annular vahre and positionedabove and adapted to seat thereon, said septum having a, plurality ofconcentric faces affording a seat for said annular valve, means adaptedto limit the lift of said valves, said circular valve bein allowed agreater lift than said annular va ve.

l. Valve mechanism interposed between a source of pressure fluid supplyand a pressure fluid reservoir comprising a valve casing, a septumdividing the easing into an inlet chamber and an outlet chamber andhaving a plurality of concentric faces limiting the downward movement ofthe valve, a light disc-like flexible annular valve, spaced-apart stopsabove. and relatively close to the valve when sea-ted so astosubstantially restrict the lift of the valve, a light disc-likeflexible circular valve above, and of smaller diameter than, the annularvalve, and means limiting the lift of the second valve but permitting agreater lift than the lift of the first valve, the second valve adaptedto seat upon the inner rim of the first valve.

5. A valve mechanism interposed between a source of pressure fluidsupply and a body, a septum dividing the body into inlet and outletchambers and provided with an annular opening circumscribed byconcentric raised seats, a light resilientannular valve having a flowpassage through the body thereof, whereby the fluid can flow from theinlet to the outlet chamber over both seats, and spaced guides for thevalve having flow channels therebetween, said valve adapted to flexunder superimposed pressure to conform to said seats and bear on thesurface thereof.

In testimony of which invention, I have hereunto set my hand, atPhiladelphia, Pa, on this 5th day of April, 1922.

STRICKLAND L. KNEASS.

